Much has been written from many perspectives about whether fisheries are currently sustainable and, to the extent that they are not, what should be done to achieve sustainability. Two figures from the report of the Food and Agriculture Organization of the United Nations, The State of the World Fisheries and Aquaculture 2016 (SOFIA),1 suggest that although unsustainable fisheries still exist, they are not the rule. The total take of capture fisheries globally has been stable for three decades, and the proportion of assessed fish stocks considered to be overfished has increased only marginally over the same period.

With the proportion of exploited stocks classed as over­fished remaining around 30 per cent since the 1990s, progress still needs to be made on making all fisheries sustainable. Vigilance is also needed to keep currently sustainable fisheries from expanding to unsustainable levels. One option would be to simply exploit everything less. Reducing fishing pressure across the board would allow the remaining overfished stocks to recover and sustainable fisheries to have greater resilience to pressures such as climate change, ocean pollution and other factors. Some proposals for ocean protection targets promote such strategies, including the call for classifying 30 per cent of the ocean as marine protected areas where no extractive resource uses would be permitted.2

It might be appropriate to consider the approach of simply fishing less if the only standard of sustainability were the status of the exploited stocks and the ecosystems in which they occur. Neither of those conditions, however, is true. Fisheries are conducted in order to provide economic returns from market sales, livelihoods to those participating in the activity, and above all, food for people. Sustainability must be found for all the outcomes—ecological, economic and social. Aside from rare and exceptional circumstances usually associated with histories of severe overfishing, merely reducing fishing would have unsustainable social and economic outcomes even if the targeted fish stocks increased.

If the only impacts of fishing less to achieve greater ecological sustainability were financial then economic policies and market measures might mitigate some negative effects on revenues. Further capital investment, which could contribute to the overcapacity of fishing fleets, might also be discouraged. In many fisheries, however, particularly small-scale fisheries, there is little scope for coastal communities to accommodate the loss of livelihoods associated with fishing. The dependence of such communities on fishing can be found not only in less developed States. The economic and social consequences of the cod moratorium in eastern Canada, for example, have been significant and have lasted far longer than the moratorium itself. In less developed States, where social support resources and alternative employment opportunities are less available, the consequences of lost fishing livelihoods are even harsher; small-scale fisheries often provide employment to multiple generations, and both men and women have important roles, so the entire base of communities can be lost. Until recently, small-scale fisheries have not been at the centre of policies or dialogue on fisheries sustainability, but that is changing.3 Perhaps with greater attention paid to these challenges, more resilient strategies can be found for helping small-scale fisheries adjust to greater limitations on fishing opportunities.

Notwithstanding the importance of the social and economic consequences, less fishing means that fisheries will produce less food. Such an outcome makes strategies of just fishing less unviable, even if the other economic and social outcomes are mitigated, because fish are crucial to global food security. In 2010, projections were made of how much more fish would be required by 2050 to keep up with human population growth and bring the hungry or malnourished up to minimum World Health Organization standards, taking into account regional variations in the proportion of fish in local diets.4 It was estimated that an additional 70-80 million metric tons would be needed, a 50 per cent increase in the current total production of capture fisheries and aquaculture. In 2016, these estimates were revisited and combined with projections of production from large-and small-scale agriculture to consider how climate change may affect future food security. It was concluded that, taking into consideration the impacts of climate change on crops and livestock, fisheries and aquaculture would have to produce an additional 100 to 120 million metric tons of fish-an increase of two thirds from present production.5 This will only be possible by fishing more, not less, and by greatly increasing aquaculture yields. Thus, the real challenge to keeping fisheries sustainable is not how to address the 30 per cent of stocks that continue to be overfished despite decades of efforts aimed at improved sustainability, but rather how to greatly increase the provision of fish to a needy human population without returning to the trend seen in the 1970s and 1980s, when the number of unsustainable fisheries increased annually.

This is a very difficult challenge, but we have much of what we need to meet it. The extrinsic factors that contribute to making fisheries unsustainable have been identified and studied. These include many inappropriate incentives from markets and Governments; high demand for limited resources, especially those of high value; the complexity and incomplete knowledge of marine production systems; poverty and lack of alternatives, which keep excessive participants in fisheries; lack of effective governance to implement appropriate measures; and the externalities of climate change and ocean pollution.6

The factors of unsustainability and many activities of fisheries that can address them are known, as are policies and measures to promote and support those activities. These have been set out in the Code of Conduct for Responsible Fisheries and its several annexes, and are available to those conducting and managing fisheries.7 This guidance includes strategies that are sufficiently precautionary in the face of the complexities and uncertainties of fisheries management, and avoid or mitigate the many ecosystem effects of fisheries, including by-catches and impacts on seabed habitats.

These messages should be seen as positive. On a fishery­-by-fishery basis, the guidance exists to diagnose the major threats to sustainability, and to select appropriate measures to address those threats. Nevertheless, the overall picture should not be taken as rosy. Even if the necessary policies and measures can be identified, they are not necessarily easy to implement. The more fishing that is needed, the more knowledge is also required—regarding both the status of the resources and the activities of the fisheries. Such knowledge does not have to be solely data-intensive scientific monitoring and assessment, although for large-scale fisheries these are the main sources of knowledge. In all scales of fisheries, the local knowledge of fishers and indigenous fishing cultures can also be valuable in informing decisions.

Knowledge for identifying appropriate measures is necessary to keep fisheries sustainable as harvesting expands, but it is not sufficient. There must be governance capacities to make decisions considered legitimate by those affected and to enforce the implementation of the measures, once adopted. This could be a capacity to make top-down decisions by a jurisdictional institution and then enact those decisions with enforcement and surveillance officers, or a capacity of local communities to embed appropriate practices in the culture and daily actions of community members. Both can be effective, but both have vulnerabilities. Top-down approaches require significant resources for assessment, management, control and surveillance, and underfunding the institutions compromises their effectiveness. In areas beyond national jurisdictions, these challenges can all be amplified, although regional fisheries management bodies can be effective if adequately supported. Community-based approaches require coherent community cultures. They can be vulnerable to some immigrants who neither assimilate in the communities nor consider their governance actions legitimate, or to technological changes that increase the impacts of traditional practices on resources or ecosystems. Ways of enhancing the effectiveness of both institution- and community-based management are receiving a great deal of attention in discussions of ocean policy and governance. Progress in such fields as marine biological diversity of areas beyond national jurisdiction has been made, albeit slowly.8

One more area of serious dialogue needs to be opened if sustainable fisheries are to be achieved. However effectively fisheries may be governed and managed, they change the ecosystems in which they occur. The total biomass of fully exploited species is reduced, typically by more than 50 per cent. There is growing evidence that more balanced harvesting of marine species may reduce the degree to which the overall ecosystem is altered by fisheries. Nevertheless, if total removals were to increase by even 50 per cent, or likely much more, to meet food security needs, marine ecosystems would be altered. Sustainable Development Goal (SDG) 14 (Conserve and sustainably use the oceans, seas and marine resources for sustainable development) will play a central role in policy discussions on keeping oceans healthy. The necessary dialogue will have to focus on what constitutes a "healthy ocean". If "as close to pristine as possible” is the de facto standard for "healthy", then even current fisheries will run counter to SDG 14, and the types of expansions of fisheries needed to help achieve SDG 2 (End hunger, achieve food security and improved nutrition and promote sustainable agriculture) will become major threats. There needs to be a serious dialogue to determine what types of alterations in marine and coastal ecosystems are sustainable, whether in the sense of maintaining options for adaptation to other conditions, if society chooses, or in other senses. The complexity of these discussions may make past efforts at achieving the sustainability of fisheries appear simple in comparison.

Notes

1 Food and Agriculture Organization of the United Nations, The State of World Fisheries and Aquaculture, 2016: Contributing to Food Security and Nutrition for All, Report (Rome, 2016). Available from http://www.fao.org/fishery/sofia/en.

6 Food and Agriculture Organization of the United Nations, "International workshop on the implementation of international fisheries instruments and factors of unsustainability and overexploitation in fisheries", Mauritius, 3-7 February 2003, FAO Fisheries Report No. 700 (Rome,2004). Available from ftp://ftp.fao.org/docrep/fao/007/y5242e/y5242eOO.pdf.

8 For further information on the Preparatory Committee established by General Assembly resolution 69/292: Development of an International legally binding instrument under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction, see http://www.un.org/depts/los/biodiversity/prepcom.htm.